TSH

Test Code

38467

CPT Codes
84443<br>Limited Access Code

Preferred Specimen

1 mL serum

Minimum Volume

0.7 mL

Other Acceptable Specimens

1 mL plasma collected in a plasma separator tube PST

Instructions

Specimen collection after fluorescein dye angiography should be delayed for at least 3 days. For patients on hemodialysis, specimen collection should be delayed for 2 weeks. According to the assay manufacturer Siemens: "Samples containing fluorescein can produce falsely depressed values when tested with the Advia Centaur TSH Ultra assay."

Transport Container

Plastic vial

Transport Temperature

room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

Methodology
Immunoassay

Setup Schedule

Set up: Daily; Report available: Next day

Reference Range

Premature Infants, 28-36 weeks
1st week of life: 0.20-27.90 mIU/L

Term Infants (>37 weeks)
Cord Blood: 1.00-39.00 mIU/L

1-2 days: 3.20-34.60 mIU/L
3-4 days: 0.70-15.40 mIU/L
5 days-4 weeks: 1.70-9.10 mIU/L
1-11 months: 0.80-8.20 mIU/L
1-19 years: 0.50-4.30 mIU/L
≥ 20 years: 0.40-4.50 mIU/L

Pregnancy Reference Ranges:
First Trimester: 0.26-2.66 mIU/L
Second Trimester: 0.55-2.73 mIU/L
Third Trimester: 0.43-2.91 mIU/L

Clinical Significance

Test is for the differential diagnosis of primary, secondary, and tertiary hypothyroidism. It is also useful in screening for hyperthyroidism. This assay allows adjustment of exogenous thyroxine dosage in hypothyroid patients and in patients on suppressive thyroxine therapy for thyroid neoplasia.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.